The projector is driven by an Arduino. To give it more than just a hard-coded existence [Michiel] included an Xbee module. This lets him connect to it with a computer in order to stream messages. One of the demo videos linked in his project log shows the web interface he coded which will push a message typed in the submission form out to the projector where it is scrolled like a marquee.

This type of spinning display is one of a few common methods for making laser projectors. In the image above you can see the optical sensor which is used to sync the diode with the spinning mirrors, each of which is responsible for a different row of pixels. He lists off several things that he learned when working on the project. We think the most important is the timing issues which go into something like this.

LG has built an interesting troubleshooting feature into some of their washing machines. This video shows the encoded audio it will output if you use the right button combination. You’re supposed to hold your phone up to the machine while talking to customer service and they’ll be able to get some type of debugging information from the dial-up modem type of sounds. If you end up decoding this audio we want to know about it! [Thanks Pedro]

MicroSD card adapter for Raspberry Pi

[TopHatHacker] was surprised to see a full-sized SD card slot on the Raspberry Pi. His temporary solution to get his microSD card working was to uses a miniSD adapter. He cut away the case and bent the pins until they lined up with the microSD card.

[Brane] built an underwater ROV from LEGO mindstorm parts. Look closely at this image and you should notice something missing. The tether that normally carries power and control lines from an ROV to the surface is missing. This is a wireless solution that lets him control the device using an Xbox controller.

The video after the break shows about five minutes of test drive footage. [Brane] has a big aquarium in which he can test the thing. Since he put it together as his senior engineering project at University it’s likely that this is a testing facility at the school. Here’s the little we know about the hardware: It’s using NXT Mindstorm parts to control the motors, with a sealed chamber for a battery. Connectivity is provided by an XBee module with an NXT adapter board called the NXTBee. A laptop with its own XBee module makes up the other end of communications. Right now [Brane] uses an Xbox controller connected to the laptop, but a standalone device would be easy to build by hacking the XBee and controller together directly.

If you’ve been playing with electronics for long enough, eventually you’ll need a nice remote control transmitter to control your RC car, airplane, or any other robotics project you have lying around. With these robotics projects comes the problem remote control, and the XBee Handheld Controller may be just the ticket to remotely control any project that comes off your workbench.

This isn’t the first remote controller we’ve seen that does just about everything, but it is the first one to include an XBee wireless transceiver to easily interface to your robotics project. The controller comes in two models, the Q4, which uses four Playstation-like joysticks, and the Q2, which uses proper remote control gimbal joysticks. Both the controllers have a slew of buttons, toggle switches, four rotary pots and a 2×20 LCD display.

After the break you can check out [Paul]’s pitch explaining what these controllers can do and showing off a hexapod robot under the control of his Q4 controller. A very neat project, and we can’t wait to see this controller out in the field.

For the uninitiated a little ice fishing primer may be in order. The majority of what you see above is a standard tip-up rig for ice fishing. Basically it lets you set many baited lines and just watch for a flag to pop up when one of them hooks a fish. Just drill a hole in the ice and drop the line through — the orange frame rests on the surface of the ice.

The add-on here is the grey box which is hiding an Xbee device. A magnet and reed switch (which can be found at the local hardware store) complete a circuit when the flag is down. But if the flag pops up the reed switch opens (or closes, we’re not sure which) and the Xbee sends an alert to a base station, which then converts that to a text message to push to your phone. As you guessed, there’s a video after the break.

So let’s say that you’re a developer on the Xbee team. You need to test the extremes of what the RF radio modules can do when in a large network. But in addition to numerous nodes, you also need to test the effects of distance on the radios. Since it’s not reasonable to distribute hundreds of the devices (each with their own power source) throughout town, you build a test setup like the 1 kilonode Xbee rig which the project manager, [Jared Hofhiens] is showing off.

He’s holding one blade from the rack-mounted system. Each of those squares is an Xbee module, there’s 32 etched onto the board. On the edge furthest from him there are a set of connectors which mate with the rack connectors, hooking the blade up to a set of terminal servers. These servers allow developers to ssh into individual modules. On the near side of the blade there’s a set of attenuation adjustment circuits. They allow adjustments of 0-40 dB of attenuation in 10 dB increments to adjust how strong the RF signals are, simulating distance between modules.

So you’ve got a really cool project that requires a wireless controller and a ton of different channels. What are you going to do? Are you going to go pick up an expensive RC controller? Nah, you’re going to build your own. This project makes a generic 20 channel controller for your projects by stuffing an SMDuino and an XBee module inside a ps2 controller. Unfortunately you lose the force feedback since you have to remove the motors to make space for the extra components and batteries. You do end up with a decently ergonomic and aesthetically pleasing controller though.